.TH std::is_enum 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::is_enum \- std::is_enum

.SH Synopsis
   Defined in header <type_traits>
   template< class T >              \fI(since C++11)\fP
   struct is_enum;

   std::is_enum is a UnaryTypeTrait.

   Checks whether T is an enumeration type. Provides the member constant value which is
   equal to true, if T is an enumeration type. Otherwise, value is equal to false.

   If the program adds specializations for std::is_enum or std::is_enum_v, the behavior
   is undefined.

.SH Template parameters

   T - a type to check

   Helper variable template

   template< class T >                                   \fI(since C++17)\fP
   inline constexpr bool is_enum_v = is_enum<T>::value;



Inherited from std::integral_constant

.SH Member constants

   value    true if T is an enumeration type, false otherwise
   \fB[static]\fP \fI(public static member constant)\fP

.SH Member functions

   operator bool converts the object to bool, returns value
                 \fI(public member function)\fP
   operator()    returns value
   \fI(C++14)\fP       \fI(public member function)\fP

.SH Member types

   Type       Definition
   value_type bool
   type       std::integral_constant<bool, value>

.SH Example


// Run this code

 #include <type_traits>

 struct A { enum E {}; };
 static_assert(std::is_enum_v<A> == false);
 static_assert(std::is_enum_v<A::E> == true);

 enum E {};
 static_assert(std::is_enum_v<E> == true);

 enum class Ec : int {};
 static_assert(std::is_enum_v<Ec> == true);

 static_assert(std::is_enum_v<int> == false);

 int main() {}

.SH See also

   is_integral    checks if a type is an integral type
   \fI(C++11)\fP        \fI(class template)\fP
   is_arithmetic  checks if a type is an arithmetic type
   \fI(C++11)\fP        \fI(class template)\fP
   is_scalar      checks if a type is a scalar type
   \fI(C++11)\fP        \fI(class template)\fP
   is_scoped_enum checks if a type is a scoped enumeration type
   (C++23)        \fI(class template)\fP
